A new report on Muslim prisoners from civil rights organization Muslim Advocates has revealed alarming truths about Muslim experiences in U.S. prisons.

Among other things, the report found that Muslims are significantly overrepresented in American prisons. Despite making up only 1 percent of the U.S. population, Muslims make up about 9 percent of the U.S. prison population. In some states, including Maryland, New Jersey, and Pennsylvania, that number is higher than 20 percent.

“We don’t know for certain why there are so many, or why the numbers are growing,” said Yusuf Saei, a Muslim Advocates legal fellow and the study’s main author. “Possible factors are the growth of the Muslim population in the U.S. generally, increased surveillance, harsher sentencing, and enforcement for Muslim communities, as well as conversions in prison.”

These findings are not entirely shocking to those familiar with how law enforcement and the criminal justice system have targeted Muslims since September 2001. According to the ACLU, the NYPD launched an entire Muslim Surveillance Program the following year, which involved infiltrating mosques and stationing police in neighborhoods with “ancestries of interest.” And Black Muslims in particular have been targeted by both government surveillance and the police state since America’s inception.

The study also looked into the ways that Muslims are treated within prisons across the country finding that “numerous muslim prisoners face obstacles to practicing faith.” Muslim Advocates found that the most commonly reported form of discrimination against Muslim prisoners involved prisons’ refusal to comply with Muslim dietary restrictions. Out of 163 Muslim prisoner cases that were brought to federal court and evaluated in the study, nearly 40 percent involved food. The study’s findings come after a report last year that a prison in Alaska was purposely starving Muslim prisoners during Ramadan by giving them pork sandwiches and not providing them with enough calories to sustain themselves while fasting.

Muslim Advocates also found that incarcerated Muslims were regularly denied requests to observe Eid al-Fitr, while Christian holiday requests were routinely approved.

The study also found that many Muslim prisoners experience obstacles to prayer and worship, often due to intentional and discriminatory practices on behalf of prisons and guards. In one cited case, Muslim prisoners were forced to pray outside, often in extreme weather conditions, and, in another, Muslims were banned from praying inside their cells. The study also noted two prisoners who were once limited to one religious service per week as a form of punishment.

While Muslim Advocates encountered numerous prisons with harmful practices that often violated the right to religious freedom, they also noted that “there are many ‘less restrictive’ and even fully accommodating prison policies that successfully facilitate Muslim practices around prayer, diet, and dress, without compromising compelling government interests in safety.”

“As civil rights lawyers, our takeaway is that many state prisons are failing to respond to the needs of this significant population of Muslims,” said Saei. “It is simply unreasonable for so many state prisons to deny these people basic necessities [...] particularly when other prisons are already doing this with ease.”

To conclude the study, Muslim Advocates included a list of best practices recommendations for state departments of corrections, pointing out that Muslim overrepresentation in prisons should be enough of an incentive to implement the suggestions nationally. The suggestions include allowing Muslims to adjust their work hours during Ramadan, training guards on how to conduct respectful searches of religious property, and allowing head coverings throughout their facilities.