I analyzed DNA from 581 complete families in the 1000 Genomes Project to search for nonparental genetic contributions that could indicate recent alien genetic manipulation. My screening of variants in 77 Mb on Chromosome 3 identified 11 families (2%) containing large fragments of DNA sequence in children that matched neither human parent. The most significant case displayed a cluster of 348 nonparental genetic variants with precise simultaneous substitution of identical fragments on both chromosomes. There is no known biological mechanism or technical error that could produce such a change. Achieving such a genetic manipulation at the time of conception with current methods is possible but difficult using CRISPR technology, which emerged in 2013. Since the studied children were born before 1990, human genetic manipulation cannot be an explanation of the observed 16 Kb substitution in homologous chromosomes. This is strong evidence for extraterrestrial genetic manipulation. Further, two unrelated families showed major nonparental insertions at the same genomic hotspot on chromosome 3, suggesting this region serves as a preferred integration site. Quality control analysis confirmed these represent genuine biological signals through low background variation in normal (98%) of studied families, contrasted with sharp nonparental variant density peaks, achieving statistical significance of p < 10^-13. Families identified as having nonparental insertions displayed a clustered density of nonparental variants 50 times stronger than normal families. The non-random chromosomal clustering and technical precision required for these insertions provide solid evidence for extraterrestrial genetic modification with technology that went beyond human capabilities at the time of conception. Additionally, my pilot analysis of two families with self-reported self-suspecting alien abduction experiences using inexpensive, generic commercial 23andMe genotyping detected similar nonparental contributions, supporting this approach for self-suspecting alien abductee volunteers to identify traces of genetic manipulations as an affordable "do-it-yourself" method. Future research should test the biological significance of alien genetic modifications and see what functions were altered in people.