What You'll Learn
The Concept
The pretrial period begins at arrest and ends at case resolution — through dismissal, plea, or trial. During this period, defendants may be detained in jail or released, with or without conditions. The decision about pretrial release is made at an initial appearance, typically within 24 to 48 hours of arrest. In most jurisdictions, the primary mechanism for securing release is cash bail — a financial deposit that is forfeited if the defendant fails to appear for court.
The cash bail system has been extensively criticized. Defendants who cannot afford bail are detained regardless of their risk level; defendants who can afford bail are released regardless of their risk level. Research has found that pretrial detention — even for short periods — is associated with higher conviction rates, longer sentences, and worse employment and housing outcomes, independent of the underlying offense. These effects are particularly pronounced for low-income defendants.
The constitutional framework for pretrial detention is established by the Bail Reform Act of 1984 and the Supreme Court's decision in United States v. Salerno, 481 U.S. 739 (1987), which upheld the constitutionality of preventive detention — detention based on predicted future dangerousness rather than flight risk alone. The Court held that pretrial detention does not violate due process when it serves a legitimate regulatory purpose and is accompanied by adequate procedural protections.
Risk-assessment instruments have been developed to provide judges with structured information about defendants' likelihood of failing to appear for court and their risk of reoffending pretrial. The Public Safety Assessment (PSA), developed by the Laura and John Arnold Foundation, uses nine factors drawn from criminal history to produce two scores: a failure-to-appear score and a new criminal activity score. Research on the PSA has found that it predicts court appearance and pretrial reoffending better than unaided judicial judgment, but that it produces racial disparities in detention recommendations.
New Jersey implemented a comprehensive bail reform in 2017, eliminating cash bail for most offenses and replacing it with a risk-based release system. Evaluations have found that the reform reduced the pretrial jail population substantially without increasing failure-to-appear rates or pretrial crime. New Jersey's experience has been cited as evidence that cash bail can be eliminated without compromising public safety, though critics note that the reform was accompanied by significant investment in pretrial services and supervision.
Pretrial supervision — conditions imposed on released defendants, such as check-ins, drug testing, electronic monitoring, or curfews — is intended to ensure court appearance and reduce pretrial reoffending. Research on the effectiveness of supervision conditions is mixed. Some conditions — particularly those that are intensive and resource-intensive — may increase the risk of technical violations and redetention without improving public safety outcomes. The appropriate level of supervision should be calibrated to the defendant's assessed risk.
The competing interests in pretrial policy are difficult to reconcile. Public safety requires that defendants who pose a genuine risk of serious harm be detained. Court appearance requires that defendants who are likely to flee be detained or supervised. Liberty requires that defendants who are presumed innocent not be punished before conviction. These interests cannot all be maximized simultaneously, and the appropriate balance reflects value judgments as much as empirical findings.
Applied Example: The Consequences of 24-Hour Detention
Research by Dobbie, Goldin, and Yang (2018) used a natural experiment in Philadelphia to estimate the causal effects of pretrial detention. They found that defendants who were detained pretrial — even for just a few days — were 13 percentage points more likely to be convicted and received sentences that were 42 percent longer than comparable defendants who were released. These effects persisted years after case resolution, affecting employment and earnings. This research illustrates how a decision made at the beginning of the criminal justice process can have consequences that extend far beyond the case itself.
Why It Matters
For Police Officers
Officers make arrests that trigger the pretrial process. Understanding how pretrial detention affects defendants — and how those effects can compound into worse outcomes for individuals and communities — provides context for the downstream consequences of arrest decisions.
For Students
Pretrial justice is one of the most active areas of criminal justice reform. Students who understand the legal framework, the evidence on detention's effects, and the competing policy approaches can evaluate reform proposals critically and contribute to evidence-based policy development.
Think About It
How does cash bail create a two-tiered system of pretrial justice based on wealth rather than risk?
What are the constitutional limits on preventive detention, and how did United States v. Salerno establish them?
How should courts balance the competing interests of public safety, court appearance, and the liberty of presumptively innocent defendants?
What does the New Jersey bail reform experience suggest about the feasibility of eliminating cash bail, and what conditions were necessary for its success?
How do racial disparities in pretrial detention compound into larger disparities at conviction and sentencing?
Sources & Further Reading
United States v. Salerno, 481 U.S. 739 (1987).
Dobbie, W., Goldin, J., & Yang, C. S. (2018). The effects of pretrial detention on conviction, future crime, and employment: Evidence from randomly assigned judges. American Economic Review, 108(2), 201–240.
Arnold Foundation. (2016). Pretrial Criminal Justice Research. https://craftmediabucket.s3.amazonaws.com/uploads/PDFs/LJAF-Pretrial-CJ-Research-brief_FNL.pdf
Lowenkamp, C. T., VanNostrand, M., & Holsinger, A. (2013). The Hidden Costs of Pretrial Detention. Laura and John Arnold Foundation.
New Jersey Courts. (2019). Pretrial Release Report. https://www.njcourts.gov/courts/assets/criminal/2019pretrialreleaserpt.pdf