Here is some history for you:
Criminal Alien Statistics - FY2018
The following is a summary of U.S. Border Patrol enforcement actions related to arrests of criminal aliens for Fiscal Years1 2016, 2017 and 2018 through 31 August.
Records checks of available law enforcement databases following the apprehension of an alien may reveal a history of criminal conviction(s). That conviction information is recorded in a U.S. Customs and Border Protection database, from which the data below is derived.
ARRESTS OF INDIVIDUALS WITH CRIMINAL CONVICTIONS
FY2016-2017 totals, and FY2018 YTD (October 1, 2017 - August 31, 2018)
Southwest Border Migration
Use of Force
Web Performance
Criminal Alien Statistics - FY2018
The following is a summary of U.S. Border Patrol enforcement actions related to arrests of criminal aliens for Fiscal Years1 2016, 2017 and 2018 through 31 August.
Records checks of available law enforcement databases following the apprehension of an alien may reveal a history of criminal conviction(s). That conviction information is recorded in a U.S. Customs and Border Protection database, from which the data below is derived.
ARRESTS OF INDIVIDUALS WITH CRIMINAL CONVICTIONS
FY2016-2017 totals, and FY2018 YTD (October 1, 2017 - August 31, 2018)
The term “criminal alien” refers to aliens who have been convicted of one or more crimes, whether in the United States or abroad, prior to interdiction by the U.S. Border Patrol; it does not include convictions for conduct that is not deemed criminal by the United States. Arrests of criminal aliens are a subset of total apprehensions by U.S. Border Patrol.
FY2016 FY2017 FY18TD
U.S. Border Patrol Criminal Alien Arrests 12,842 8,531 6,259
TOTAL CRIMINAL CONVICTIONS BY TYPE
FY2016-2017 totals, and FY2018 YTD (October 1, 2017 - August 31, 2018)
This table organizes convictions of criminal aliens by type of criminal conduct. Because some criminal aliens may be convicted of multiple criminal offenses, total convictions listed below exceed the total arrests noted in the table above.
FY2016 FY2017 FY18TD
Assault, battery, domestic violence 1,007 692 506
Burglary, robbery, larceny, theft, fraud 825 595 322
Driving under the influence 2,458 1,596 1,062
Homicide, manslaughter 8 3 3
Illegal drug possession, trafficking 1,797 1,249 816
Illegal entry, re-entry 7,060 4,502 3,637
Illegal weapons possession, transport, trafficking 237 173 98
Sexual offenses 155 137 78
Other2 2,544 1,851 1,298
https://www.cbp.gov/newsroom/stats/cbp-enforcement-statistics/criminal-alien-statistics
Note: the 2018 numbers are only up to Aug 31, so appear lower, but mostly are not when extrapolated out for the complete year.